In communication networks, such as Internet Protocol (IP) Multimedia Subsystem (IMS) networks, communication sessions are routed through a communication network from an originating device (e.g., a voice over IP (VoIP) telephone, plain old telephone service (POTS) telephone, mobile phone and/or cellular phone) to a terminating device (e.g., a VoIP telephone, a POTS telephone, mobile phone and/or cellular phone). Server-based URIs are widely used in IMS networks to route communication sessions. An example server-based URI is john.doe@serviceprovider.net, where john.doe identifies a particular subscriber and serviceprovider.net identifies the host and/or service provider that provides one or more communication services to john.doe via that server-based URI.